Reply to emails from a shared mailbox

We have a shared mailbox for our customer service and i try to build something with Powerapps and Flow to get better control over the conversation and who is working on the cases - something like a ticket system light.

However, i have the idea how to deal with it with sharepoint lists, filled with flow.

What i desperatly miss is a "reply to an email from a shared mailbox". Of course, i could use "send email from a shared mailbox" but the Original meassage id, that is used to thread emails in email clients, will be lost and the email will not appear in the original conversation.

Is there a way to add the Message ID of the initial email as conversation id to the outgoing e-mail?

Or, as other option, to add the shared mailbox as "from" in the current existing "reply to an email" action, as you can do it in outlook.